A bit of an update.
I've been unable to locate a replacement condenser, it being one side of the points and to all reports, obsolete. So today a nice new electronic coil arrived. Also a new air filter to replace the dust that was the original.
New coil soon fitted and tried and very healthy spark from the plug. So next everything was put back together. Then the throttle cable decided to let me know it was practically seized.
Off with that and after several applications of 3in1 oil and pulling back and forth, it freed to an acceptable level of movement.
Right! It was now time to see if it would run. To start with, I just squirted some petrol into the carb and gave the pull cord a few jerks. This resulted in a couple of coughs from the exhaust. Promising!
Some petrol into the tank and lets try again after another dose down the carb. It fired and ran. Briefly! Tried again with same procedure and got same result. It wouldn't take any notice of the throttle position. Choke shut and opened ok. Bit of head scratching, sitting and thinking. Staring at the bench. Hang on! What's this?
In the box that had held all the bit's and bob's, was a small rod and light spring. The one that connects throttle butterfly to lever. So now all I have to do is remember/workout just how it fits. I jest not.